Flash Flood Products Overview

Drainage area affected by the forecasted heavy precipitation and potential flash floods. Yellow/Red/Purple = drainage area affected with a high probability to exceed a 2/5/20 year return period magnitude.

Reporting points showing the furthest downstream locations where the forecasted probability (%) of extreme runoff accumulations exceeds a 2 (yellow), 5 (red), or 20 (purple) year return period magnitude. Enlarged triangles represent the most flash flood prone location within each administration unit where the forecasted probability is >= 10% of the 5 year return period and the lead time to the runoff peak is <= 60 hours. Persistence shows the number of prior forecasts, including the current one, where at least one reporting point in each administration region has a forecasted probability >=10% of the 5 year return period.

Using the gauge-adjusted precipitation estimates and nowcasts, the flash flood hazard level is estimated by first computing the upstream basin-aggregated rainfall over the drainage network (resolution: 1km) and then comparing the observed values with a set of reference thresholds to determine the flash flood hazard level (yellow - low; orange - medium; red - high). The ERICHA FF hazard level is displayed in a loop with 15-minute time interval. It shows the estimated flash flood hazard level for several hours in the past up to current time and nowcasts up to 6 hours (when the loop bar turns red). This product was developed in the  ERICHA  project.

Daily gauge-adjusted radar rainfall accumulation is estimated for the last 24 hours finishing at the selected time stamp (00:00, 12:00 UTC). In EFAS this product is only available for the past 7 days. This product was developed in the  ERICHA  project.

1-h precipitation accumulation estimated from the European OPERA radar rainfall composites. This product is displayed in a loop with 15-minute time interval. It shows the estimated precipitation for several hours in the past up to current time and nowcasts (when the loop bar turns red) up to 6 hours. Deterministic precipitation nowcasts are generated by Lagrangian extrapolation. This product was developed in the ERICHA project. Recently, a multiplicative adjustment factor map (retrieved from long-term comparison with rain gauge observations) is applied to compensate for systematic biases in the original OPERA radar rainfall estimates. The gauge-adjustment module has been developed within the  SMUFF  project.